fig6

Figure 6. (A) STEM-EDS elemental mapping of core-shell Co/Zn-ZIF@ZIF-67. (B) SEM, (C) TEM and (D) AC STEM images of core-shell Co-N₃C₁@GC. Co K-edge (E) FT-EXAFS, (F) XANES and (G) the corresponding XANES fitting curves of Co-N₃C₁@GC and reference samples. (H) Schematic illustration of the formation of Co-N₃C₁@GC. (I) LSV curves, (J) Tafel plots and (K) LSV curves before and after 5000 cycles of Co-N₃C₁@GC. (L) A polarization curve of the battery and corresponding power density plot^[121]. EDS: Energy-dispersive spectroscopy. EDS: Energy-dispersive spectroscopy; STEM: scanning transmission electron microscopy; AC STEM: aberration-corrected scanning transmission electron microscopy; FT-EXAFS: fourier transforms extended X-ray absorption fine structure; XANES: X-ray absorption near edge structure; LSV: linear sweep voltammetry.